Paul in the book of Acts was chased, stoned,and imprisoned for preaching the gospel. In every city he always went to the synagogue first, then went to the gentiles. He did this because as the word of God says, it is to the Jew first, then to the Greek. Salvation came to the Jews first. Some believed, some didn’t. But God has always kept His word to every man. In the book of Romans, Paul prays for the nation of Israel, they would see and understand the gospel and believe. And that we shouldn’t condemn them because of their unbelief. He said until the fulness of the gentiles comes in, then Israel will believe. God called them first. And that we should have mercy on them. As it says in Romans 11:29, for the gifts and calling of God are without repentance. (KJV).